Former Fighting Back Partnership chief Tony Pearsall was arrested Sunday night on suspicion of driving under the influence and hit-and-run after he allegedly struck a parked car in a shopping center lot, Interim Police Chief Joseph Kreins said Monday.

Pearsall, 66, is also a former Vallejo Police captain, former city councilman and is married to Councilwoman Stephanie Gomes.

Pearsall did not return phone calls or e-mails seeking comment, but his Vallejo attorney, Dan Russo, said his client was not under the influence of drugs or alcohol but was having an “adverse reaction to Ambien,” a prescription medication used to treat insomnia.

“When it all comes out, it”s one of those tragic accidents,” Russo said.

Pearsall takes Ambien because of pain associated with recent surgeries, Russo said. “It”s the only way he can sleep,” he added.

Kreins said police received a call about 9:16 p.m. after a witness reportedly saw a vehicle hitting a parked car in the Lucky”s supermarket lot at Tuolumne and Redwood streets.

The witness apparently flagged down a police car temporarily parked in the lot and reported the incident, Sgt. Herman Robinson said.

Witnesses gave officers a description of the vehicle and a license plate number which came back to a vehicle in the 200 block of El Camino Real, Robinson said.

Officers went to that location trying to find the car, Robinson said.

As the patrol car turned south on El Camino Real officers saw the suspect vehicle approaching north on the same street, Robinson said.

The vehicle was driving on the wrong side of the street at a slow speed, Robinson said. Pearsall was the only person in the vehicle, he added.

Officers turned on the patrol car”s siren to stop the car.

Kreins said Pearsall stopped nose-to-nose in front of the police car, while Robinson said he struck the police vehicle”s bumper, causing minor damage.

Pearsall was reportedly taken out of the vehicle and detained after allegedly showing symptoms of being under the influence of either alcohol or prescription drugs, Robinson said.

Pearsall was taken to Kaiser Permanente Medical Center for a blood test and was cited and released at the hospital, police officials said.

The test results are not yet available, but Russo said he”s confident the only drug in his system to show will be the Ambien.

Russo said Pearsall also takes “mild painkillers” due to his medical issues, and had had a “minuscule” amount of alcohol prior to driving, but “not enough to register on the blood test.”

Apparently, Pearsall had taken a dose of Ambien with the intention of going to bed, but then had to go to the store to buy some medications for his wife, Russo said.

“He had forgotten he had taken the medication – that”s one of the problems with this drug,” he said.

“He was not consciously driving under the influence,” Russo stressed.

In early June, Pearsall announced he had resigned from the Fighting Back Partnership executive director position after he had been placed on paid leave for about 90 days. He had worked for the community nonprofit since May 2008.

Fighting Back is a 22-year-old nonprofit originally formed as a community-based effort to combat drug and alcohol use. The organization was formed to create collaborations and partnerships with businesses, residents and government to improve neighborhoods and strengthen families, according to its website.

Pearsall served one term on the City Council, from 2003-2007, and worked in the Vallejo Police Department for more than 35 years.